Collagens in the extracellular matrix (ECM) provide a physical barrier to tumor immune infiltration, while also acting as a ligand for immune inhibitory receptors. Transforming growth factor-β (TGF-β) is a key contributor to shaping the ECM by stimulating the production and remodeling of collagens. TGF-β activation signatures and collagen-rich environments have both been associated with T cell exclusion and lack of responses to immunotherapy. Here, we describe the effect of targeting collagens that signal through the inhibitory leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) in combination with blockade of TGF-β and programmed cell death ligand 1 (PD-L1). This approach remodeled the tumor collagenous matrix, enhanced tumor infiltration and activation of CD8+ T cells, and repolarized suppressive macrophage populations, resulting in high cure rates and long-term tumor-specific protection across murine models of colon and mammary carcinoma. The results highlight the advantage of direct targeting of ECM components in combination with immune checkpoint blockade therapy.
Lucas A. Horn, Paul L. Chariou, Sofia R. Gameiro, Haiyan Qin, Masafumi Iida, Kristen Fousek, Thomas J. Meyer, Margaret Cam, Dallas Flies, Solomon Langermann, Jeffrey Schlom, Claudia Palena
The gut microbiome shapes local and systemic immunity. The liver is presumed to be a protected sterile site. As such, a hepatic microbiome has not been examined. Here, we showed a liver microbiome in mice and humans that is distinct from that of the gut and is enriched in Proteobacteria. It undergoes dynamic alterations with age and is influenced by the environment and host physiology. Fecal microbial transfer experiments revealed that the liver microbiome is populated from the gut in a highly selective manner. Hepatic immunity is dependent on the microbiome, specifically the bacteroidetes species. Targeting bacteroidetes with oral antibiotics reduced hepatic immune cells by approximately 90%, prevented antigen-presenting cell (APC) maturation, and mitigated adaptive immunity. Mechanistically, our findings are consistent with presentation of bacteroidetes-derived glycosphingolipids to NKT cells promoting CCL5 signaling, which drives hepatic leukocyte expansion and activation, among other possible host-microbe interactions. Collectively, we reveal a microbial/glycosphingolipid/NKT/CCL5 axis that underlies hepatic immunity.
Joshua C. Leinwand, Bidisha Paul, Ruonan Chen, Fangxi Xu, Maria A. Sierra, Madan M. Paluru, Sumant Nanduri, Carolina G. Alcantara, Sorin A.A. Shadaloey, Fan Yang, Salma A. Adam, Qianhao Li, Michelle Bandel, Inderdeep Gakhal, Lara Appiah, Yuqi Guo, Mridula Vardhan, Zia Flaminio, Emilie R. Grodman, Ari Mermelstein, Wei Wang, Brian Diskin, Berk Aykut, Mohammad Khan, Gregor Werba, Smruti Pushalkar, Mia McKinstry, Zachary Kluger, Jaimie J. Park, Brandon Hsieh, Kristen Dancel-Manning, Feng-Xia Liang, James S. Park, Anjana Saxena, Xin Li, Neil D. Theise, Deepak Saxena, George Miller
SMAD4, a mediator of TGF-β signaling, plays an important role in T cells to prevent inflammatory bowel disease (IBD). However, the precise mechanisms underlying this control remain elusive. Using both genetic and epigenetic approaches, we revealed an unexpected mechanism by which SMAD4 prevents naive CD8+ T cells from becoming pathogenic for the gut. Prior to the engagement of the TGF-β receptor, SMAD4 restrains the epigenetic, transcriptional, and functional landscape of the TGF-β signature in naive CD8+ T cells. Mechanistically, prior to TGF-β signaling, SMAD4 binds to promoters and enhancers of several TGF-β target genes, and by regulating histone deacetylation, suppresses their expression. Consequently, regardless of a TGF-β signal, SMAD4 limits the expression of TGF-β negative feedback loop genes, such as Smad7 and Ski, and likely conditions CD8+ T cells for the immunoregulatory effects of TGF-β. In addition, SMAD4 ablation conferred naive CD8+ T cells with both a superior survival capacity, by enhancing their response to IL-7, as well as an enhanced capacity to be retained within the intestinal epithelium, by promoting the expression of Itgae, which encodes the integrin CD103. Accumulation, epithelial retention, and escape from TGF-β control elicited chronic microbiota-driven CD8+ T cell activation in the gut. Hence, in a TGF-β–independent manner, SMAD4 imprints a program that preconditions naive CD8+ T cell fate, preventing IBD.
Ramdane Igalouzene, Hector Hernandez-Vargas, Nicolas Benech, Alexandre Guyennon, David Bauché, Célia Barrachina, Emeric Dubois, Julien C. Marie, Saïdi M’Homa Soudja
Cellular senescence plays an important role in human diseases, including osteoporosis and osteoarthritis. Senescent cells (SCs) produce the senescence-associated secretory phenotype to affect the function of neighboring cells and SCs themselves. Delayed fracture healing is common in the elderly and is accompanied by reduced mesenchymal progenitor cells (MPCs). However, the contribution of cellular senescence to fracture healing in the aged has not to our knowledge been studied. Here, we used C57BL/6J 4-month-old young and 20-month-old aged mice and demonstrated a rapid increase in SCs in the fracture callus of aged mice. The senolytic drugs dasatinib plus quercetin enhanced fracture healing in aged mice. Aged callus SCs inhibited the growth and proliferation of callus-derived MPCs (CaMPCs) and expressed high levels of TGF-β1. TGF-β–neutralizing Ab prevented the inhibitory effects of aged callus SCs on CaMPCs and promoted fracture healing in aged mice, which was associated with increased CaMPCs and proliferating cells. Thus, fracture triggered a significant cellular senescence in the callus cells of aged mice, which inhibited MPCs by expressing TGF-β1. Short-term administration of dasatinib plus quercetin depleted callus SCs and accelerated fracture healing in aged mice. Senolytic drugs represent a promising therapy, while TGF-β1 signaling is a molecular mechanism for fractures in the elderly via SCs.
Jiatong Liu, Jun Zhang, Xi Lin, Brendan F. Boyce, Hengwei Zhang, Lianping Xing
Mice with experimental nerve damage can display long‑lasting neuropathic pain behavior. We show here that 4 months and later after nerve injury, male but not female mice displayed telomere length (TL) reduction and p53‑mediated cellular senescence in the spinal cord, resulting in maintenance of pain and associated with decreased lifespan. Nerve injury increased the number of p53‑positive spinal cord neurons, astrocytes, and microglia, but only in microglia was the increase male‑specific, matching a robust sex specificity of TL reduction in this cell type, which has been previously implicated in male‑specific pain processing. Pain hypersensitivity was reversed by repeated intrathecal administration of a p53‑specific senolytic peptide, only in male mice and only many months after injury. Analysis of UK Biobank data revealed sex-specific relevance of this pathway in humans, featuring male‑specific genetic association of the human p53 locus (TP53) with chronic pain and a male-specific effect of chronic pain on mortality. Our findings demonstrate the existence of a biological mechanism maintaining pain behavior, at least in males, occurring much later than the time span of virtually all extant preclinical studies.
Arjun Muralidharan, Susana G. Sotocinal, Noosha Yousefpour, Nur Akkurt, Lucas V. Lima, Shannon Tansley, Marc Parisien, Chengyang Wang, Jean-Sebastien Austin, Boram Ham, Gabrielle M.G.S. Dutra, Philippe Rousseau, Sioui Maldonado-Bouchard, Teleri Clark, Sarah F. Rosen, Mariam R. Majeed, Olivia Silva, Rachel Nejade, Xinyu Li, Stephania Donayre Pimentel, Christopher S. Nielsen, G. Gregory Neely, Chantal Autexier, Luda Diatchenko, Alfredo Ribeiro-da-Silva, Jeffrey S. Mogil
Mushroom spine loss and calcium dyshomeostasis are early hallmark events of age-related neurodegeneration, such as Alzheimer’s disease (AD), that are connected with neuronal hyperactivity in early pathology of cognitive brain areas. However, it remains elusive how these key events are triggered at the molecular level for the neuronal abnormality that occurs at the initial stage of disease. Here, we identify downregulated miR-339-5p and its upregulated target protein, neuronatin (Nnat), in cortex neurons from the presenilin-1 M146V knockin (PSEN1-M146V KI) mouse model of familial AD (FAD). Inhibition of miR-339-5p or overexpression of Nnat recapitulates spine loss and endoplasmic reticulum calcium overload in cortical neurons with the PSEN1 mutation. Conversely, either overexpression of miR-339-5p or knockdown of Nnat restores spine morphogenesis and calcium homeostasis. We used fiber photometry recording during the object-cognitive process to further demonstrate that the PSEN1 mutant causes defective habituation in neuronal reaction in the retrosplenial cortex and that this can be rescued by restoring the miR-339-5p/Nnat pathway. Our findings thus reveal crucial roles of the miR-339-5p/Nnat pathway in FAD that may serve as potential diagnostic and therapeutic targets for early pathogenesis.
Hao-Yu Zou, Lin Guo, Bei Zhang, Si Chen, Xin-Rong Wu, Xian-Dong Liu, Xin-Yu Xu, Bin-Yin Li, Shengdi Chen, Nan-Jie Xu, Suya Sun
Latency reversal strategies for HIV cure using inhibitor of apoptosis protein (IAP) antagonists (IAPi) induce unprecedented levels of latent reservoir expression without immunotoxicity during suppressive antiretroviral therapy (ART). However, full targeting of the reservoir may require combinatorial approaches. A Jurkat latency model screen for IAPi combination partners demonstrated synergistic latency reversal with bromodomain (BD) and extraterminal domain protein inhibitors (BETi). Mechanistic investigations using CRISPR-CAS9 and single-cell RNA-Seq informed comprehensive ex vivo evaluations of IAPi plus pan-BET, bD-selective BET, or selective BET isoform targeting in CD4+ T cells from ART-suppressed donors. IAPi+BETi treatment resulted in striking induction of cell-associated HIV gag RNA, but lesser induction of fully elongated and tat-rev RNA compared with T cell activation–positive controls. IAPi+BETi resulted in HIV protein induction in bulk cultures of CD4+ T cells using an ultrasensitive p24 assay, but did not result in enhanced viral outgrowth frequency using a standard quantitative viral outgrowth assay. This study defines HIV transcriptional elongation and splicing as important barriers to latent HIV protein expression following latency reversal, delineates the roles of BET proteins and their BDs in HIV latency, and provides a rationale for exploration of IAPi+BETi in animal models of HIV latency.
Shane D. Falcinelli, Jackson J. Peterson, Anne-Marie W. Turner, David Irlbeck, Jenna Read, Samuel L.M. Raines, Katherine S. James, Cameron Sutton, Anthony Sanchez, Ann Emery, Gavin Sampey, Robert Ferris, Brigitte Allard, Simon Ghofrani, Jennifer L. Kirchherr, Caroline Baker, JoAnn D. Kuruc, Cynthia L. Gay, Lindsey I. James, Guoxin Wu, Paul Zuck, Inmaculada Rioja, Rebecca C. Furze, Rab K. Prinjha, Bonnie J. Howell, Ronald Swanstrom, Edward P. Browne, Brian D. Strahl, Richard M. Dunham, Nancie M. Archin, David M. Margolis
Trained immunity refers to the long-lasting memory traits of innate immunity. Recent studies have shown that trained immunity is orchestrated by sustained changes in epigenetic marks and metabolic pathways, leading to an altered transcriptional response to a second challenge. However, the potential heterogeneity of trained-immunity induction in innate immune cells has not been explored. In this study, we demonstrate cellular transcriptional programs in response to 4 different inducers of trained immunity in monocyte populations at single-cell resolution. Specifically, we identified 3 monocyte subpopulations upon the induction of trained immunity, and replicated these findings in an in vivo study. In addition, we found gene signatures consistent with these functional programs in patients with ulcerative colitis, sepsis, and COVID-19, suggesting the impact of trained-immunity programs in immune-mediated diseases.
Bowen Zhang, Simone J.C.F.M Moorlag, Jorge Dominguez-Andres, Özlem Bulut, Gizem Kilic, Zhaoli Liu, Reinout van Crevel, Cheng-Jian Xu, Leo A.B. Joosten, Mihai G. Netea, Yang Li
Targeted monoclonal antibody (mAb) therapies show great promise for the treatment of transplant rejection and autoimmune diseases by inducing more specific immunomodulatory effects than broadly immunosuppressive drugs routinely used. We recently described the therapeutic advantage of targeting CD45RC, expressed at high levels by conventional T (Tconv) cells (CD45RChi), their precursors, and terminally differentiated T (TEMRA) cells, but not by regulatory T cells (Tregs; CD45RClo/–). We demonstrated efficacy of anti-CD45RC mAb treatment in transplantation, but its potential has not been examined in autoimmune diseases. Autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy (APECED) is a rare genetic syndrome caused by loss-of-function mutations of autoimmune regulator (AIRE), a key central tolerance mediator, leading to abnormal autoreactive T cell responses and autoantibody production. Herein, we show that, in a rat model of APECED syndrome, anti-CD45RC mAb was effective for both prevention and treatment of autoimmune manifestations and inhibited autoantibody development. Anti-CD45RC mAb intervention depleted CD45RChi T cells, inhibited CD45RChi B cells, and restored the Treg/Tconv cell ratio and the altered Treg transcriptomic profile. In APECED patients, CD45RC was significantly increased in peripheral blood T cells, and lesioned organs from APECED patients were infiltrated by CD45RChi cells. Our observations highlight the potential role for CD45RChi cells in the pathogenesis of experimental and human APECED syndrome and the potential of anti-CD45RC antibody treatment.
Marine Besnard, Céline Sérazin, Jason Ossart, Anne Moreau, Nadège Vimond, Léa Flippe, Hanna Sein, Grace A. Smith, Stefania Pittaluga, Elise M.N. Ferré, Claire Usal, Ignacio Anegon, Annamari Ranki, Michail S. Lionakis, Pärt Peterson, Carole Guillonneau
The functional integrity of CD8+ T cells is tightly coupled to metabolic reprogramming, but how oxidative stress directs CD8+ T cell metabolic fitness in the tumor microenvironment (TME) remains elusive. Here, we report that SUMO-specific protease 7 (SENP7) senses oxidative stress to maintain the CD8+ T cell metabolic state and antitumor functions. SENP7-deficient CD8+ T cells exhibited decreased glycolysis and oxidative phosphorylation, resulting in attenuated proliferation in vitro and dampened antitumor functions in vivo. Mechanistically, CD8+ T cell–derived ROS triggered cytosolic SENP7–mediated PTEN deSUMOylation, thereby promoting PTEN degradation and preventing PTEN-dependent metabolic defects. Importantly, lowering T cell–intrinsic ROS restricted SENP7 cytosolic translocation and repressed CD8+ T cell metabolic and functional activity in human colorectal cancer samples. Our findings reveal that SENP7, as an oxidative stress sensor, sustains CD8+ T cell metabolic fitness and effector functions and unveil an oxidative stress–sensing machinery in tumor-infiltrating CD8+ T cells.
Zhongqiu Wu, Haiyan Huang, Qiaoqiao Han, Zhilin Hu, Xiao-Lu Teng, Rui Ding, Youqiong Ye, Xiaoyan Yu, Ren Zhao, Zhengting Wang, Qiang Zou
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